Amazon.com's newly acquired book-readers social network, Shelfari, has a bad reputation. The main charges lodged: It has grown its userbase through a shady techniques such as automatically sending site invites to everyone in a new user's email address book. It's also believed to engage in "astroturfing" —- specifically, pretending to be users in blog comments to buff up its image. Gawker last year described the site as "basically social networking rapists" — a perhaps inelegant phrasing, but one that gets the point across.Shelfari CEO Josh Hug — how can you dislike a man whose last name is "Hug"? —blamed the whole mess on "an unexperienced but well-meaning intern." Ironically, the company that exposed Shelfari's tactics was rival books social network LibraryThing. AbeBooks, a recently acquired Amazon.com subsidiary, owns 40 percent of LibraryThing. Who will be motivated to report on Shelfari's user-gathering tactics now? Oh, right — that would be you, gentle reader !